.At the moment [09.01.2020] it is not fully understood which files are necessary
to boot a Linux or an bare metal application onto the HPS of a Cyclone 5 / 10 or Aria chip
Every detail which not fully clear will be emphasized as questionable.
Requirements
All steps to format / setup a bootable SD card can only be performed within a Linux.
An installation of INTEL SoC FPGA EMBEDDED DEVELOPMENT SUITE, so the tool
alt-boot-disc-util (mk(p)image) is present.
Background
The boot process of the HPS consists of several stages:
- Boot ROM
- Hard coded into the chip
- It's purpose is to detect the selected boot source
- Perform minimal Setup of the HPS
- Load the next Boot stage [Preloader / u-boot-spl] into the On chip RAM [OCRAM]
therefore the preloader / SPL u-boot is limited to 64 kByte on Cyclone 5 devices - Preloader
- Perform additional HPS initialization
- Bring up SDRAM
- Load the next boot stage from Flash to SDRAM and jump to it
- Preloader-optins:
u-boot - SPL
SoC EDS - MPL [Altera bare-metal libraries - HWLibs]
- For Cyclone 5 devices, the preloader consists of 4 identical copies. each 64 kB in size,
256 kb in total
- When generating the preloader, it can be necessary to manually add a checksum and
a mark for recognition into the binary, the tool mk(p)image can perform these additions - Main Bootloader
- Load Linux [u-boot] or Bare Metal Application into the RAM
- Jump to it.
In case of Linux, load Kernel, followed by the loading of the Linux rootfs
Partitions within the SD card
The SD card can be partitioned or not, a partitioned SD card offers the advantage of a separation / persistent data storage.
Partitions of the SD card:
Partition Required for Size
W95 FAT32 (LBA) Kernel and Device Tree Blob > 20 MB
Linux ext(2/3 or 4) Linux Distribution > 150 MB to 2 GB
Altera / a2 SPL u-boot and Main u-boot >= 1 or 2 MB
The first partition need to be the vFat partition, best practice: vFat, Linux and a2 partition
Unknown - partition for u-boot config script and how to setup (uboot.scr)
vfat-partition: optional - Linux-Config-Script / main u-boot instead a2-partition
Format the SD card
To partition the SD card, Linux offers the command line tool fdisk [sfdisk].
BEWARE! fdisk [sfdisk] can operate on every disk within the system and does not ask for approval.
Identify your SD card
Inserd the Sd card into the system, start a console [Ctrl + Alt + t] and type:
lsblk → list the disks conected to the system / Get SD-card-path
Example output:
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 120G 0 disk
├─sda1 8:1 0 112G 0 part /
├─sda2 8:2 0 1K 0 part
└─sda5 8:5 0 8G 0 part [SWAP]
sdc 8:32 1 7,2G 0 disk
└─sdc1 8:33 1 1M 0 part
sr0 11:0 1 1024M 0 rom
RM = Removable ? → sdc is the SD card with one partition sdc1
Format the card - Manual approach:
To format the card, start the tool fdisk by typing:
sudo fdisk /dev/sdc -> sudo=grant root, enter password fdisk=tool /dev/...=SD card
The command promt changes to Command (m for help)
Type p to list all existing partitions.
Type d to erase a partition.
Type n to edit a new partition.
Type t to set the partition type (default is Linux / 83).
Type a to mark partition as active.
Output for p: For convenience, the partition table listed is the one which the SD card needs to be setup to
Sizes may vary
Disk /dev/sdc: 7740 MB, 7740588032 bytes
239 heads, 62 sectors/track, 1020 cylinders, total 15118336 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x982b3f12
Device Boot Start End Blocks Id System
/dev/sdc1 2048 616448 307200+ c (W95 FAT32 (LBA))
/dev/sdc2 616449 3074049 1228800+ 83 Linux
/dev/sdc3 3074050 3094530 10240+ a2 Unknown
Step 1: Erase all partitions → Type d and select a partition number to delete or go with the suggested one
Repeat for all partitions
Step 2: Create a partition → Type n.
One can type in all required values by hand, but the tool offers usefull values by default.
To accept them, yout press enter.
Partition type → Select p ; Partition number → Enter ; First sector → Enter
Last sector → +size{K,M,G} / example: 20 MB partition → +20M
Step 3: Set partition type → Type t
c=W95 FAT32 (LBA) a2=Altera boot partition 83=Linux, default value
Step 4: Repeat step 2 and 3 until all partitions are created
Step 5: Write the new table to th SD card → Type w
Step 6: Close programm → Type q
Format the card - Automated approach:
Copy to a textfile and save the following in between ----- .
------------------------------
unit: sectors
/dev/sdb1 : start= 2048, size= 204800, Id= c
/dev/sdb2 : start= 206848, size= 4096000, Id=83
/dev/sdb3 : start= 4302848, size= 4096, Id=a2
/dev/sdb4 : start= 0, size= 0, Id= 0
------------------------------
To create the partition table run:
sudo umount /dev/sdX* (unmounts device)
sudo sfdisk /dev/sdX < PathToTextFile
(To read the partition table from a storage device - sudo sfdisk -d /dev/sdX > PathToTextFile)
Data of each partition
Before writing data to the partitions, unmount the device
sudo umount /dev/sdX*
and plage the SD card in and out of the card reader.
W95 Fat32 partition
The W95 Fat32 partition needs to be formated.
( sudo umount /dev/sdX* )
sudo mkfs -t vfat /dev/sdXp (p=partition number, needs to be 1)
After the operation finishes, use a data browser to copy the
Linux kernel / zImage(.bin) and the device tree blob / socfpga.dtb.
ext(2/3/4) partition
The ext(2/3/4) partition is formated via:
sudo mkfs.ext3 /dev/sdXp (p=partition number, should be 2)
After the operation finishes, use a data browser to copy the
Linux root file system / rootfs to it.
An other approach is needed for a compressed root file system.
Befor decompressing a ... .tar.gz file to the SD card, it needs to be mounted to
a mounting point. This requires an existing folder to write to.
Usually these folder is placed inside the mnt folder, for example:
sudo mkdir /mnt/card (create mounting point folder)
Mount it:
sudo mount /dev/sdXp /mnt/card (p=partition number, should be 2)
Extract the ... .tar.gz file to the partition:
sudo tar -xvf pathToCompressed.tar.gz -C /mnt/card/ (x=decompress v=show progress -C=extract to)
sudo sync (imported, empty all buffers)
a2 partition
This partition need no formatting, the data needs to be copied with the tool
alt-boot-disk-util .
The tool should be in the folder:
\intelFPGA\18.1\embedded\host_tools\altera\diskutils
Copy the SPL u-boot.bin and the Main u-boot.img to it, change to the directory:
cd pathToAlt-boot-disk-util
and run:
sudo pathToAlt-boot-disk-util -p preloaderImage.bin -b mainU-boot.img -a write /dev/sdX (the tool finds the a2 partition)
Lastly, unmount the Sd card ( sudo umount /dev/sdX* ) and test it.
(The tool dd can also be used to write the preloader - sudo dd if=pathToSplUboot of=/dev/sdXp seek=0 bs=64k conv=fsync)